Why Dilution Charts Don't Always Work

I used to swear by essential oil dilution charts after finishing my basic aromatherapy certification program. I even went as far to tell others they were wrong with their dilution rates. Oh how I was WRONG - I found out why dilution charts don't always work.

Honestly, I do not promote dilution charts. I don’t like to post essential oil charts regarding dilution very often. Do you know why?

I can tell you it isn’t because they aren’t needed. Sometimes, they absolutely are needed. I don’t post them though because of all the variables that can affect dilution.

Dilution charts are created and based on the average “healthy” individual adult that has no medical conditions and takes no medications. An individual’s personal needs and condition for which they are using essential oils can and do vary for every situation.

Dilution charts do not take anyvariables into consideration. They are meant as guidelines - not hard and fast rules that are applicable to every person, every situation or for every essential oil or other aromatic product so I do not use them often the way most do. Let me explain.

What should be considered when using dilution charts?

Below are several key pieces of information that I consider when using dilution ratios from charts. Identifying these helps me determine if a dilution chart can be used or if I need to do something different than what the chart provides for.

How old is the individual?

• Children and elderly have a much lower dilution rate than the average healthy adult that most charts are written for.
• In most cases if we are talking daily use, 0.2% up to 1% might work.
• Acute conditions will vary in dilution depending on the essential oils used. I try to keep dilutions under 5% and up to 5% for these age groups though.
• For infants, if I can use hydrosolsversus potent essential oils, I will. In some cases using essential oils can be avoided by using the right carrier oil! If I do need to use any essential oils topically on a baby I do try to stay below 0.5%. I am ultra conservative with infants but more often than not, these low amounts do the trick when topical applications are needed.

What is the severity of their condition?

• When using essential oils topically, generally if the condition is one that is acute a higher dilution rate can be used. If it is an acute condition for myself like a muscle sprain/pull, I will use up to 20% depending on the essential oils used.
• If the condition is something like a superficial cut, often a hydrosol is more than enough to soothe it. So in this case using essential oils may not be needed at all.
• If you can use less, do! For example, if I am getting a massage that is a deep tissue and want to add an essential oil that has chemical components that offer anti-inflammatory actions, I might only need 1%-2%.

Generally, if you know a low dilution will get the job done, use the lowest dilution. Save the highest dilution for when it is truly needed.

Will it be used daily?

As mentioned before, depending on the individual, daily use will have different dilution guidelines based on age or development and condition.

Using something with a 12% dilution ratio on a daily basis is…well it is over kill.

Small infants and toddlers are often better served with hydrosols versus essential oils. If using an essential oil topically you might start with 0.1% to 0.5%. As the age and development increases for the average “healthy” individual, so will the dilution rate.

What part of the body is it for?

While everyone understands that our face may be more sensitive to various products that are applied, with dilution charts it seems we forget that this is true with essential oils.

Using essential oils on the face requires a much lower dilution. 

• For daily use anywhere from 0.05% to 1% can be used depending on the essential oils used.
• For spot treatments on acne and other skin concerns where essential oils are used, we still want to use no more than 2% for 1-2 days.

Keep in mind this does not apply to every essential oil as some have risks that do not make them suitable for the face. These risks have everything to do with their chemistry.

Does the essential oil carry specific risks?

This is another key component to using essential oils. Not every essential oil can be used the same. Many have varying daily maximum recommended dilutions depending on their chemistry.

Lemongrass, cinnamon bark, Tea Tree, Lavender, and even Lemonessential oil all have varying recommended maximum dilution rates. While Tea Tree and Lavender will work for most charts, using even 1% of cinnamon bark could be sensitizing if used daily for a long period of time. Lemon can create higher phototoxic risks if used at higher than 2%.

Are there other things to consider when using dilution charts? You betcha!

Proper dilution should be based on the actual weight versus drops when formulating.

This is something I cannot stress enough. Most charts are created with drops of essential oils versus the weighed carrier oils that are set to grams or ounces. Dilution rates should be measured using a scale as well. 

Orifice reducer size can affect the dilution.

• Not every company uses the same size orifice reducer. There are a few companies that utilize very large reducers, some that use medium size, and some that use a combination of small, medium and large.
• The viscosity of an essential oil will also determine how much will escape through the orifice reducer and will also play a role in using inaccurate dilution rates. Think Vetiver versus Lemon essential oil in the same size orifice reducer.

For those curious, I measure my essential oils and fixed oils in grams for a more accurate measurement to attain an accurate dilution rate.

Dilution rates can also vary from one essential oil to another based on their chemistry.

As I mentioned earlier, many essential oils can be utilized using a standard dilution chart. However, there are several that require a different approach due to their chemistry.

We have some essential oils that are considered phototoxic, some that are considered hot oils, and others that are known skin sensitizers. Each of these types of risks are based on specific chemical components that naturally occur in essential oils. A few examples are below.

Phototoxic Essential Oils

• In some phototoxic essential oils, coumarins can create phototoxic reactions when not diluted properly.
• A few of these essential oils have maximums that are less than 1% where some might be 2-3% depending on their chemistry.
• There are several essential oils that are considered phototoxic that just do not work with a one size fits all dilution chart.
• Why? Because they do not take into consideration phototoxic essential oils and each one's unique chemistry that has varying amounts of coumarins.

"Hot" Oils & Other Sensitizing Essential Oils

• Lemongrass has a very low dermal maximum rate of 0.7% due to its chemistry so using it as you would a Lavender can potentially put you at risk for a topical reaction. 
• Cinnamon is another essential oil with a very low dermal maximum due to the constituent cinnamaldehyde. It is often referred to as a irritating oil.
• Oregano, which is touted by many enthusiasts for its antibacterial properties, is another essential  oil with a low dermal maximum.

So when is it appropriate to use higher dilution ratios?

Higher dilutions can in most cases be used for a very short period of time for an acute condition assuming the individual is the average “healthy” adult. For example, a pain reducing blend might be used on a severe muscular strain for a day or two at say 15-20% depending on the essential oils used.

Understanding that every essential oil is unique from batch to batch and you need to look at the chemistry will also allow you to have a higher dilution rate in some instances for some essential oils. For example, if the methyl eugenol content is very lower than the ISO for rose absolute, it would be safe to use it in higher amounts but you NEED to know what the ISO is first and what your current batch levels are.

A few notes about those handy charts…

Dilution charts are meant as guidelines. Not the hard and fast rules that many have made them out to be. As aromatherapy is not black and white, it should be clear now that dilution rates are not so clear cut either. So don’t toss out your charts, but don’t assume they will work for every person, in every situation, or with every essential oil.

Please, by all means, keep diluting your essential oils. But do not assume the charts you have become oh so familiar with are meant to be taken as the end all be all when it comes to diluting essential oils. There is so much more to the art and science of dilution. 

If you need help with getting a safe dilution rate, ask questions. There is one book in particular that is fantastic for learning the various intricacies of dilution - Tisserand & Young Essential Oil Safety 2nd Edition. Chat with a qualified aromatherapist that has studied the chemistry and maybe even get a consultation session with them to learn more about the essential oils you love.